The present invention pertains to automatic switches for controlling electrical appliances. Particularly, it is a smart switch called Occupant Counter Control Switch, or OCCS, which automatically turns on and off electrical appliances such as lights by capable of keeping track and displaying the number of occupants in a room via the process of counting up when detecting a person entering the room and counting down when detecting a person leaving the room. When the display shows the count number greater than zero, indicating the presence of occupant/occupants in the room, and insufficient ambient light is detected, the OCCS turns on the lights and constantly keeps them on as long as the room is occupied. When the count or display reaches zero as the last person exiting the room, the OCCS immediately turns off the lights.
With today high price of energy and air pollution are concerned, a smart switch such as OCCS will help saving energy in every household and will consequently help keeping the earth atmosphere less polluted. It will be very useful for the families having teenagers who tend to be careless about turning off the lights after leaving the room, or for the families having young children who, are not tall enough to reach the switch, need help from the adults to turn on or off the lights every time they entering or leaving a room. OCCS will automatically take care of turning on and off the lights for them. Parents will no longer concern of any light be left on unintentionally in the house to waste power and to generate heat that keeps air conditioning to run excessively to waste even more energy. Thereby, the present invention OCCS devotes to save energy and to offer convenience in daily life.
Most of the automatic switches in the prior arts, such as the U.S. Pat. No. 5,946,209, simply turn on the lights for a preset period of time when detecting a person's movement in the motion-detection zone of the PIR sensor. When the preset time expires, the lights are turned off until the PIR sensor detects another human motion to turn on the lights again for another preset time period. This becomes very annoying when a person in a room sits almost motionless during the time he/she reading the book and the lights suddenly turns off upon timing out. If prolong the preset time for the possibility of the PIR sensor to detect another human motion before time out, the lights will stay on too long a period of time from the moment the room is unoccupied; therefore, energy is wasted. Moreover, this mentioned prior art is not very useful for application in a room that has partitioned wall or object blocking the view of the PIR sensor.
Other prior invention, U.S. Pat. No. 5,374,854, offered some similar functions to those of the present invention OCCS but did not provide a means to allow manually change the count value and a means to display the figure of the count value. This becomes ambiguous when the automatic switch of this said prior art miscounts, caused by human, and there is no means for recognizing the erroneousness; for example, when a person inadvertently stands in front of the sensor for a conversation with someone and his movements mislead the automatic switch to count up or count down excessively. The result of these excessive counts would unexpectedly turn off the lights and would be very inconvenient for the occupants who had to get out of and then reenter into the room to restart a new count cycle for turning on the lights properly. For a quick solution, someone would have certainly depressed the provided button on this said prior art to manually turn on the lights instead; however, this solution defeats the purpose of having a switch operates automatically since the last person who leaving the room has to manually turn off the lights. But more than likely that no one minds to turn off the lights because no one knows for sure that he/she is the last person in the room. With the OCCS, someone just enters the correct number of occupants and the OCCS takes care of turning off the lights automatically upon the last person exiting the room.
To overcome the mentioned problems and to make ease of use, the preferred embodiment of the present invention OCCS provides the means to display the figure of the count that indicates the number of occupants in the room and the means to allow manually adjusting the count value; therefore, the user can visually acknowledge the erroneousness, accidentally caused by the user, and be able to easily correct the count by pressing the button on the OCCS. The provided digital display also associated with the provided two push buttons to serve other functions of fine-tuning. With the intention of saving energy, the said digital display is programmed such that no more than one segment of the digit is flashed at any time. Each segment of the digit is flashed quickly and sequentially making the whole digit appears solidly illuminated.
Another reason for this invention is of its economical benefit. Only one OCCS needed at the entrance of the main room that contains several partitioned rooms that share the same light source (see FIG. 1), whereas the mentioned automatic switch of the prior art, whose sensor's view is blocked by the partitioned walls, must be installed in every partitioned room to control its own light source.